Sabah police chief Omar Mammah said initial investigations showed the factory had operated for seven years and traffickers had bought the pangolins from illegal hunters for distribution locally.

He added that Sabah had "been implicated in over 40 tons of pangolin smuggling since August 2017, including 13 tons of African pangolin scales".

The latest seizures echo the discovery of logbooks kept by another pangolin trafficking ring in 2009, which revealed 22,200 pangolins had been killed and 834.4kg of scales sourced and supplied over 13 months.

There was another massive seizure of pangolin scales at a Sabah port and in Malaysia's capital Kuala Lumpur in 2017, suggesting that Sabah has emerged as a hub for trafficking the critically endangered creatures.

Image:Pangolins are believed to be the most trafficked animals on Earth

In December last year, Sky News obtained footage of a gang member prodding and poking a pangolin for amusement in South Africa.

Four of the traffickers involved were arrested and their contraband was handed over to an animal hospital.

According to international organisation WWF, an estimated 116,990 to 233,980 pangolins were killed between 2011 and 2013 based on reported seizures.

But experts believe seizures represent as little as 10% of the actual number of pangolins being illegally trafficked.